Strong gas smell when starting

Jhill

If you do an ecm reset after warm how quickly and how high (or low I guess) do the short term fuel trim jump? Meaning does it jump to something like -15 and keep pegging there as long term drops.

Z_ealot

It’s been a while since i did that so i woukdnt be sure about the exact behavior it exhibited. What i can tell you about the last time i did that is that i do remember it struggling and having a rough idle after i performed an ecu reset and performed an idle air relearn, it did finally smooth out after a few minutes though.

Z_ealot

I did the best I could getting a chart of what the fuel trims are doing with what tools I have, keep in mind the blue and gray lines are short term fuel trims for banks 1 and 2 and the orange and red are the long terms, this was taken today with ambient outside temps at 92 degrees while driving normally

Jhill

Little hard to read, is this idling or driving? I was more just after seeing the short term % pegged - after a reset to idicate if you have an injector leaking or something else causing a large unaccounted increase in fuel. Unsure on the z but I've rarely actually had leaky injectors (maybe I'm just lucky). Your comment of it having a hard/stumbling start after reset would indicate an issue (especially if it says a hot start after reset). May be time to check fuel pressure (typical they fail low but I have on vary rare occasion had overly high pressures). Can check residual pressure at same time.

Z_ealot

The peaks on the blue and gray stft are when it’s pegged at +25%, what might be interesting to you is that before i started recording the ltft was at -8% at a hot start with stft pegged at +25% for a good 10 seconds and then the engine stumbled and the fuel trims reversed with ltft shooting up to +10% and stft dropping to -15%. The graph i posted was recorded after this while i was driving in the city so it was a mix of acceleration and idling

Jhill

So what's stft and ltft after full warm and leveled out, idle and like a steady cruise, no radical acceleration etc.

Z_ealot

At idle after warming up ltft sits at -10.2% with stft fluctuating between +3% and +20%, usually i see the +20% and above after the engine is heatsoaked and idling. During cruising with rpm at a steady 2500 ltft usually sits at -3 to -5% with stft between 0 to +3%


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Jhill

Ok so your cruising numbers look good. Idle I would like a lower number but not terrible for ltft but the huge fluctuations in short term don’t look so good (although not a vq expert but that doesn’t seem great to me). How many miles on this engine? No roughness or intermittent misfires at lower RPM/idle?